Infections Flashcards
CMV - IgM + - what % have infection?
25%
Can persist for months after primary infection, and recur with reactivation
Symptoms primary CMV
Usually asymptomatic
May have a viral illness
Risk factors for CMV acquisition
Child care workers (12% seroconversion/y)
parents with children in day are
CMV general population seroconversion
2%/y
Prenatal diagnostic testing
Amnio for CMV PCR
at least 6 weeks after primary infection
Sensitivity ~100% >21/40
USS low sensitivity and specificity `
USS features of CMV
Microcephaly Ascites Oligo/poly Abdominal/intracranial calcification hydrocephalus Hydrops IUGR Hepatomegaly
Prevention of CMV transmission
- No role of IVIG in prevention
Management of confirmed foetal CMV infection
- TOP, with the knowledge it is difficult to predict the severity of infection based on PCR and USS
- IVIG - better clinical outcomes for babies at 1 year in one non-randomised trial
CMV - risk of transmission with seroconversion
- risk of symptomatic CMV
- risk of sequelae
30%
- with transmission: (overall 10-20% risk long term squeal of congenitally infected child)
- 10% symptomatic > 50% sequelae
- 90% asymptomatic > 10% sequelae
Clinical signs of symptomatic CMV
- high early mortality
- microphaly
- seizures
- chorioretinitis
- developmental delay
- sensorineural hearing loss
Newborn Ix for CMV
- Examination
- Serology
- Urine/salive PCR
> if + then opthal and radiological (USS and MRI)
> Rx w oral valganciclovir
Practices for reducing infection with CMV
- Assume children <3y in your care have CMV
- Thoroughly wash hands with soap and water after touching child/toys/nappies/feeding/bathing etc
- Don’t share cups, plates, utensils, toothbrushes or food
- Do not kiss the child on or near the mouth
- Do not share a bed w the child
- Do not share towels or washcloths
Prevalence rubella
1/100 000 pregnancies
Symptom rubella infection
50% asymptomatic
Vague coryzal symptoms
Examthem: maculopapular, face>trunk, resolves face>trunk
+/- polyarthralgia
+/- tender lymphadenopathy
Forchemers spots (rose like) on soft palate
Diagnosis of rubella infection
4x increase in IgG titre (usually 2/52)
IgM +
Culture +
Amnio/CVS PCR
Diagnosis of neonatal congenital rubella infection
IF IgM + at birth > retest 1/12
Infant Rubella IgG higher for longer than expected (maternal IgG lasts ~6/52)
Chance of foetal infection across gestations (Rubella)
T1 80%
T2 30%
T3 100%
Congenital rubella infection vs congenital rubella syndrome
Infection: - MC - SB - Birth defects - Asymptomatic - IUGR Syndrome: = constellation of birth defects - hearing impairment - congenital heart defect - cataracts/glaucoma - pigmentary retinopathy
Rx rubella in pregnancy
Prevention - vaccine prepreg
Supportive care
Rx of complications e.g. steroids for thrombocytopenia
Manage the foetus: discuss TOP (esp <16/40), no direct in utero Rx
Manifestations of congenital infection EARLY
- Hearing loss 60%
- Heart defects 45% (PDA, pulmonary stenosis)
- Microcephaly 25%
- Cataracts 25%
- IUGR 25%
- hepatosplenomegaly/jaundice/purpura/pneumonitis
- meningoencephalitis
Manifestations of congenital rubella infection LATE
- Hearing loss
- Intellectual disability
- DM
- Thyroid dysfn
- Progressive pan-encephalitis
- Immune defects
Neonatal follow up after rubella infection
- Clinical attendants at birth should be rubella immune
- IX: IgM, Urine PCR, culture urine and throat swab (can take weeks)
- Opthal, cardiac and hearing assessments at birth
- Regular clinical assessment
- May be infectious for 1y of life
Risk of congenital defects by gestational age (Rubella)
T1 ~85%
13-16/40 ~35%
>16/40 - rare
HSV seroprevalence
HSV 1= 60%
HSV 2 = 20%
Risk of HSV transmission if in genital tract in labour (recurrent)
HSV 1 15%
HSV 2 <0.01%
Overall 1-3%
HSV - difference between primary and non-primary first infection?
Primary - HSV 1 and 2 serology negative
Non-primary = seropositive for other serotype
Risk of HSV transmission for primary HSV?
If maternal seroconversion well before efelivery e.g. prior to 30-24/40, then as for recurrent.
No maternal seroconversion - 25-50%
Can you get in utero HSV infection?
Yes
Rare
<1%
Can cause abortion, PTB and IUGR
Scalp clip with known genital HSV?
No
Increases transmission RR 6.8!
Indications for CS with HSV?
- New HSV diagnosed in labour
- Primary HSV diagnosed late in pregnancy
- After maternal discussion with recurrent lesions in labour
Exposed neonate (primary or systemic infection), or neonate with symptoms (skin lesions, seizures, sepsis, low plt, deranged LFTs, DIC, resp distress, corneal ulcers)
Ix: LP, LFTs, FBE, HSV PCR blood, surface swabs
Immediately commence IV Aciclovir20mg/kg TDS
Recurrent genital HSV lesins in labour
Leave membranes intact as long as possible
Avoid FBS
Avoid instrumental delivery
Expedite delivery
Listeria - organism
Bacteria Listeria monocytogenes Aerobic, facultative anaerobe Motile B-haemolytic Gram + rod Tumbling motility by light microscopy Grows well at refrigeration temperatures Predilection for the placenta and CNS
Listeria - Symptoms
Febrile flu like illness Malaise / HA / Backache Abdo pain Pharyngitis Conjunctivitis Diarrhoea ARDS Asymptomatic (1/3)
Ix Listeria
Blood culture
Genital tract gram stain and culture
Rx Listeria
Amoxycillin/Ampicillin 2g Q6H IV x14/7
Gent x 14/7
(Pen allergy Trimethoprim/Sulphamethoxazole - not in T1, w folate)
Incidence Listeria
0.3/100 000
Foetal mortality w maternal Listeriosis T2/3?
~50%
Asymptomatic individuals with consumption of food implicated in outbreak of Listeria - Rx?
Yes (suggested)
Amoxyl 2-3g/d
Incubation Listeria
Broad
1-67 days
Preg average 6/52
Neonatal symptoms of Listeriosis
Granulomatosis infantiseptica - placenta, cord or post pharyngeal granulomas, small skin granulomas, pustular skin rash
MEc liquor < 34/40
Pneumonitis
Purulent conjunctivitis
Neonatal Ix and Rx
Culture: placenta, swabs, blood cultures, urine and CSF
CXR
FBE
Rx: Amoxycillin and Gent (14-21 days dependent on culture results)
Perinatal listeriosis
Early onset <7/7
- often fulminant disease
- mort 20-60%
Late onset 7/7-6/52
- usually meningitis or sepsis
- mort 10-20%
Symptoms of Malaria infection
Parasitaemia peaks T2 Fever (may be periodic) / Chills/ Sweats Myalgia Fatigue Nausea Janudice Diarrhoea Abdo pain Cough Pregnancy: - MOre severe disease - More hypoglycaemia and ARDS - More splenomegaly - More anaemia (may protect against placental malaria)
Risks of Malaria to pregnancy
MC IUGR PTB PNM Congenital infection Maternal anaemia/death
Management Malaria in pregnancy
- PRevention
- Hb and Plts
- Falciparum (80%) - Quinine and Clindamycin, or Artensunate (complicated)
- Vivax - Chloroquinine
ABCD of Malaria prevention
Awareness of risk (highest risk papua/solomons/vanauatu/subsaharan africa)
Bite prevention (insecticide, repellant (50% deet) nets, clothes)
Chemoprophylaxis (dependent on area of travel and trimester - Mefloquine safe)
Diagnosis and treatment must be prompt
Symptoms of severe malaria
Coma Hypoglycaemia (secondary to hyperinsulinaemia - common with Quinine) Shock Pulmonary oedema (ARDS) Convulsions renal failure Coagulopathy Renal failure Metabolic acidosis Severe anaemia
Risk of congenital Malaria?
Most when infection around the time of delivery
8-33%
Send the placenta
All babies thick and thin films within first 28 days
Hep C Incidence Oz
1-2%
Hep C risk of sexual transmission
<5%
Which Hep C genotypes respond best to treatment?
3,4,5 - 55% response
0,1,2 - 30% response
Rx w Interferon and rubaviron
What is the risk of vertical transmission of Hep C?
5% overall
RNA - <1%
RNA + 11%
RNA + and HIV 16%
Active drug users at higher risk of transmission
What are the implications of HCV RNA - ?
- Low level viraemia
- False + Ab test
- Past cleared infection
- Still must test the infant at 18/12
How should you test the baby from a HCV infected mother?
Abs at 12/12 - most uninfected babies will be negative
If AB + check RNA and LFTs
Can you treat HCV in pregnancy?
No - Rx is contraindicated
Should refer for consideration of post partum treatment
What factors increase the risk of vertical transmission of HCV?
- RNA +
- high viral load
- HIV co-infection
- PROM
- Invasive procedures
Can women w HCV breastfeed?
Yes
If cracked nipples consider discarding milk while waiting for them to heal
What is the risk of vertical transmission of HIV?
~45% without treatment
<2% with treatment
PRevalence HIV
Geography dependent
England 0.1%
What symtoms may occur with HIV infection?
Primary: - Fatigue - Lymphadenopathy - Fever - Rash Other: - Persistent generalised lymphadenopathy - Weightloss - Fevers - Diarrhoea - Encehalopathy
What are some opportunistic infections w HIV?
- Pneumocyctis
- Cerebral Toxo
- CMV retinitis
- TB
- Mycobacterium avium
- Karposi
- NHL
- Cryptococcus
Outline features of pretest counselling
- Confidentiality
- Ascertain risk factors and timing of potential exposure
- Ascertain details on previous testing
- Outline why the test is done
- Outline contact tracing requirements
- Implications of results
- Confirm results will be given in person
Effect of pregnancy on HIV:
- No major effect on progression, incl to AIDS
- Opportunistic infections may be less aggressively investigated or treated, esp if HIV status unknown
- Normal pregnancy associated with a reduction in cell medicated immunity - there is a decrease in number but NOT a decrease in % of CD4 cells
Effect of HIV on pregnancy:
- Increased risks: MC, PTB, IUGR (esp w advanced disease)
- No increase in congenital anomalies
HIV - factors that increase MTCT:
- High viral load
- Serovenoversion during pregnancy
- Advanced maternal disease
- Poor immunological status (low CD4)
- PROM (>4h doubles the risk)
- Preterm labour
- Vaginal delivery
- Antepartum invasive procedures (CVS, Amnio, FBS)
- Intrapartum invasive procedures (epis, FSE, instrumental)
- Prem
- Low BW
- Breastfeeding and mixed breast/bottle feeding
- Smoking
- Choreoamnionitis
Management of HIV in pregnancy:
- Other sexual health screening
- MDT
- Cotrimoxazole and Folate IF CD4<200, AIDS or previous pneumocystis
- HAART for: maternal wellbeing, or from 24/40 if from PMTC, stay on if already on. (Zidovudine and lamivudine +/- 3rd agent
Risks in pregnancy of HAART
Protease inhibitors increase GDM
Increased risk PET/IUGR
Immune reconstitution inflammatory syndrome (IRIS) (paradoxical worsening of a condition on commencement of HAART esp VZV, HSV)
Intrapartum management
- CS reduces transmission, but unknown if benefit after one of labour or SROM
- May consider VD if undetectable VL 4-6/52 prior to delivery
- Early cord clamping and bath the baby may reduce transmission
- Bottle feed
- Universal precautions
Which patients with HIV get intrapartum Zidovudine?
- those w high viral load at 36 weeks (>50 copies/ml, between 50-400/ml may consider, >400 definitely)
- Late presenters (get additional raltegravir or nevi rapine depending on VL)
Are there foetal risks of ART?
- No described adverse events
- No HIV embryopathy described
- Efavirenz and Didanosine are terotogenic, stavudine shouldn’t be prescribed in pregnancy
How should be treat the baby?
Dependent on high vs low risk MTCT
- low risk: Zidovudine
- High risk: multi drug therapy, + PJP prophylaxis until HIV infection excluded
Start as soon as possible after birth
For 2-4 weeks depending on gestation at birth
Test the baby (W DNA or RNA PCR) at 6 weeks and 3 months, at least 2 weeks after prophylaxis has stopped
Only test w Ab > 18/12
Who should we test for TB?
HIV +
Close contact w TB
Recent arrival from area of high prevalence
Symptomatic
How should we test for TB?
Tuberculin skin test (unaffected by pregnancy)
IGRA (interferon gamma release assay)
Physical examination
Signs of TB
- Any chest sign - most commonly upper lobe crackles , can have tracheal deviation secondary to fibrosis and scarring, dullness to percussion over the clavicle
- Lymphadenopathy
- Erythaema nodosum
- Extrapulmonary infection: LN, bone, liver, spleen, bone marrow, caecum, CNS, eye
Effect of pregnancy on TB
- No evidence of increased disease progression
- Congenital TB via umbilical cord is rare
- Neonatal TB via maternal airborne transmission is a concern in developing countries
Management of TB in pregnancy
Similar to non-pregnant
MDT
Active TB in pregnancy should be treated immediately
Active dx w supervised course of more than 1 drug that the organism is sensitive to (RIPE):
Rifampicin > Vit K secondary to cytochrome induction
Isoniazid > Pyridoxine to reduce peripheral neuritis
Pyrazinamide
Ethambutol
> Monitor LFTs
Send the placenta for culture and histopath
How should the baby of a TB + mother be treated?
Normally the mother is not infectious within 2 weeks of treatment
Sputum + mothers > Rx baby w Isoniazid (or drug that the organism is sensitive to ) usually for 6 months
Give the baby the BCG vaccine
Women should continue to breastfeed
Symptoms of neonatal TB
Resp distress Poor feeding Hepatosplenomegaly Fever Lymphadenopathy
Which babies should get the BCG vaccine
Aboriginal babies
Born to mothers w TB
Infants of migrant parents
Those travelling to area of high incidence of TB
Streptomycin in pregnancy?
No!
cat D
Known teratogen
May cause congenital deafness
Risk factors for GBS
- 18/24
- GBS bacturia (correlation with more heavily colonised baby and high risk of EOGBS)
- Previous GBS affected baby
- Intrapartum fever >38 degrees
Early onset GBS incidence
1/1000 all pregnancies
Untreated GBS + 1/200
70% of infants born to GBS + mothers are colonised
90% symptomatic within 12h of birth
Culture screening versus risk factor based screening
RR 0.46 for prevention of EOGBS.
(This was a retrospective cohort study)
CDC, ACOG and RANZCOG support
RCOG does not support (? not cost effective)
Anorectal collection of GBS swab - increased detection?
Yes
25%
Request sensitivities if penicillin allergic
Rate maternal anaphylaxis to penicillin
1/100 000
Less severe reactions in 7-10%
Penicillin hypersensitivity
Cephazolin 2g IV, then 1g Q8H
Anaphylaxis
Clindamycin 600mg IV Q8H (30% resistance) or Vancomycin
Reduction in EOGBS w chemoprophylaxis
1.5/1000 > 0.3/1000
Late onset GBS has remained unchanged (>1/52)
What are the infective stages of Toxoplasmosis?
i. Oocyte - in cat faeces, infective after 1-5 days
ii. Tachyzoite
iii. Bradyzoite - in undercooked meat/soil/fruit and veg - contained in cysts this not penetrable by ABs. Need to wait until develop into bradyzoites
Incidence of Toxo infection in pregnancy
1-8/1000 (highest France)
What are the symoptoms of maternal Toxo infection
May be asymptomatic
Can have fever, malaise, fatigue, headache +/- lymphadenopathy
Toxo - risk of foetal infections
increases with GA Preconceptin 0% (unless immunocompromised) T1 15% >likely severe outcomes T2 45% > intermediate risk outcomes T3 70% > usually mild infection
What are some USS findings of Toxo
Hyperechoic lesions/calcifications
VM - usually symmetrical and bilateral
Changes can be rapidly progressive
NOT SB/IUGR
Diagnosis of Toxo infection
- Serology - 2 weeks apart. IgM last 10/12. Can check IgG avidity +/- IgA.
- Amnio PCR > 4/52 after infection
- Placental histopath (cysts, deciduitis, villous sclerosis, chronic vascular thromboses, +/- free trophozoites)
Rx Maternal Toxo
Controversial if any Rx reduces MTCT
Foetal infection should be treated as it reduces the serious neurological squealer and death.
NNT mat inf 18
NNT foetal inf 3
Spiramycin 1g PO TDS > doesn’t cross placenta and thus won’t treat an infected foetus
OR
Pyrimethamine and Sulphonamide (+ Folate)
Prevention of Toxo
Avoid unfiltered water Avoid travelling S America (more severe infection) Wash fruit and veg Cook meat thoroughly Avoid cat faeces Excellent hand hygiene
What is the classic triad of neonatal Toxo?
Chorioretinitis
Hydrocephalus
Intracranial calcifications
What examinations should be performed on the newborn with clinical suspicion of toxo?
Physical exam - chorioreitinitis - seizures- - fever - hepatosplenomegaly - pneumonitis - anaemia - jaundice - lymphadenopathy Eye exam LP Cranial imaging for calcifications and hydroceph Hearing exam Follow up serology
Rx neonatal toxo
examination and Ix
If infection, even if asymptomatic Rx w pyrimethamine for 6/12 (+ folate)
What is the prevalence of VZV sero+?
95%
What is the risk of embryopathy w VZV infection in pregnancy
Low
28/40 no reports
What are the symptoms of congenital varicella?
Limb hypoplasia Skin spots Nerological abnormalitis Structural eye damage MEntal retardation 50%
What is the infectious period for varicella?
From 48h prior to rash up to when the lesions are crusted over
What is defined as ‘significant exposure’ to varicella?
Same household
Face to face for 5 minutes
same room 1h
How do you manage significant exposure to varicella?
No PHx chichenpox
Unknown or neg IgG -
- 96h consider oral acyclovir if at risk (second half of pregnancy, smoker, immunocompromised, EO complications > IV)
The patient remains infectious for up to 1/12 after ZIG
What are defined as maternal complications of VZV?
- Pregnant women more prone to complications and excess morbidity
- New lesions ater 6 days
- ongoing fevers after 6 days
- haemorrhagic rash or bleeding
- respiratory symptoms
- neurological sympotms
What is the role of amnio in VZV infection?
Generally not advised - low risk of congenital effects
- Use USS (5/52 post infection) or MRI to guide prognosis
How accurate is a hx of chicken pox for serology?
97-99%
Possibly less accurate in women born or raised overseas
How should you manage maternal VZV at term?
Delay delivery 5-7 days to allow transfer of antibodies Organise neonatal opthal exam at birth Rx ZIG (no benefit once chicken pox occur)
